Company sales: Exclusive agreement versus auction

While auction proces­ses for compa­nies were still the great excep­tion in Germany in the early 1990s, they are now a common proce­dure. With the profes­sio­na­liza­tion and inter­na­tio­na­liza­tion of tran­sac­tion support, the auction has estab­lished itself as the proce­dure of choice for many. — In the mean­time, howe­ver, a trend toward exclu­sive agree­ments is beco­ming noti­ceable again. What are the advan­ta­ges (disad­van­ta­ges) of not having an auction)?